Hi Buggin, We spent many vacations in the late 1960s and early 1970s in Reston because our uncle was one of the first contractors to begin building in the model town, but we haven’t seen it since 1980, and we expect much has changed. This is a Saddleback Caterpillar Moth as you can see from this matching image on BugGuide. Though we have not shortage of stinging Saddleback Caterpillar images, this is the first we have posted of the adult moth.